1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // This provides a wrapper around system calls which may be interrupted by a 6 // signal and return EINTR. See man 7 signal. 7 // To prevent long-lasting loops (which would likely be a bug, such as a signal 8 // that should be masked) to go unnoticed, there is a limit after which the 9 // caller will nonetheless see an EINTR in Debug builds. 10 // 11 // On Windows, this wrapper macro does nothing. 12 // 13 // Don't wrap close calls in HANDLE_EINTR. Use IGNORE_EINTR if the return 14 // value of close is significant. See http://crbug.com/269623. 15 16 #ifndef BASE_POSIX_EINTR_WRAPPER_H_ 17 #define BASE_POSIX_EINTR_WRAPPER_H_ 18 19 #include "build/build_config.h" 20 21 #if defined(OS_POSIX) 22 23 #include <errno.h> 24 25 #if defined(NDEBUG) 26 27 #define HANDLE_EINTR(x) ({ \ 28 decltype(x) eintr_wrapper_result; \ 29 do { \ 30 eintr_wrapper_result = (x); \ 31 } while (eintr_wrapper_result == -1 && errno == EINTR); \ 32 eintr_wrapper_result; \ 33 }) 34 35 #else 36 37 #define HANDLE_EINTR(x) ({ \ 38 int eintr_wrapper_counter = 0; \ 39 decltype(x) eintr_wrapper_result; \ 40 do { \ 41 eintr_wrapper_result = (x); \ 42 } while (eintr_wrapper_result == -1 && errno == EINTR && \ 43 eintr_wrapper_counter++ < 100); \ 44 eintr_wrapper_result; \ 45 }) 46 47 #endif // NDEBUG 48 49 #define IGNORE_EINTR(x) ({ \ 50 decltype(x) eintr_wrapper_result; \ 51 do { \ 52 eintr_wrapper_result = (x); \ 53 if (eintr_wrapper_result == -1 && errno == EINTR) { \ 54 eintr_wrapper_result = 0; \ 55 } \ 56 } while (0); \ 57 eintr_wrapper_result; \ 58 }) 59 60 #else 61 62 #define HANDLE_EINTR(x) (x) 63 #define IGNORE_EINTR(x) (x) 64 65 #endif // OS_POSIX 66 67 #endif // BASE_POSIX_EINTR_WRAPPER_H_ 68
